This invention relates generally to a folding knife having a blade pivotally carried within a liner and a shell pivotally attached to the liner.
Folding knives typically include an elongated handle portion which defines a blade receiving compartment. A blade is pivotally connected to the handle, and when the knife is closed, the blade is received within the blade receiving compartment. When the knife is to be used, the blade is pivoted outwardly to a retracted state from the blade receiving compartment.
A common problem with such conventional folding knives is that they require two hands to operate. One hand is required to hold the handle of the blade, and the other hand is required to grasp and extract the blade from the chamber and to pivot the blade outwardly to the retracted position. Oftentimes this requires users to take their eyes away from their work while they open the blade, causing an inconvenience. Switchblade knives may be opened with one hand, however, such knives may be outlawed in numerous jurisdictions.
Another problem with conventional folding knives is that when the blade is in its retracted state within the blade receiving chamber, the chamber is not covered, and dirt and debris may enter the chamber and foul the pivoting mechanism of the blade. Prior folding knife designs have included U.S. Pat. No. 4,730,393, issued to Coburn, which discloses a knife having a rotatable scale. U.S. Pat. No. 770,118, issued to Rowland, discloses a hunting knife having a handle and guard connected by a rule-joint. U.S. Pat. No. 586,849, issued to Ibelli, discloses a knife having tool implements. U.S. Pat. No. 847,206, issued to Saunderson, discloses a pocket knife having a stirrup and separate handle sections. U.S. Pat. No. 939,091, issued to Riggs, discloses a hunting knife having a gearing system. U.S. Pat. No. 337,858, issued to Neuhaus, discloses a folding knife having inner and outer cover members. U.S. Pat. No. 1,486,725, issued to Brown, discloses a knife having a sheath pivotally attached to a handle. U.S. Pat. No. 4,227,303, issued to Brooker, discloses a knife having a pivotal blade. U.S. Pat. No. 1,270,727, issued to Hanstein, discloses a knife having a pivoting cover.
Another problem associated with knives is the continuous requirement for sharpening of the blade. Because sharpening the blade can be a time-consuming process requiring a certain amount of skill, users often fail to keep their blades sharpened. British Patent No. 1,499,460 discloses a pocket knife having sharpening disks which are located within a channel on each side of a blade. When the blade is closed, the sharpening disks are moved along the channel to contact and sharpen the blade. A spring biases the sharpening disks toward a pivotal connection between the blade and the handle. British Patent No. 298,797 discloses a knife having a sharpening device which may be moved along the blade of a knife by the user, when the blade is in a closed position. U.S. Pat. No. 4,426,779 discloses a holder for a knife which has two beveled sharpening rollers which are spring biased toward one another and which can be used to sharpen a blade.
While various folding knife designs are available, they may present limitations which interfere with a compact, easy to manufacture device.